Fig. 3: Second-order hinge skin effect.
From: Experimental probe of point gap topology from non-Hermitian Fermi-arcs
a A parallelogrammic sample. b, c Measured pressure field distributions of the non-Hermitian and Hermitian cases at the frequency of \(4.75\,{{\rm{kHz}}}\). Two point sources with a phase difference of \(0.5\pi\) are placed at the positions marked as red stars in (a). d, e Measured pressure fields in the outmost unit cell of the hinge states in the non-Hermitian and Hermitian cases at the frequency of \(4.75\,{{\rm{kHz}}}\) for \({k}_{z}=-0.5\pi /L\).
